The present invention relates to an automobile switching circuit responsive to switches mounted on a steering wheel through a common conductor.
In automotive vehicles it is desired that switches for activating the horn, wipers, lights and automatic speed control apparatus and the like be mounted on the steering wheel from the standpoint of safety driving. Since the steering wheel rotates freely on a steering column, the addition of extra wires for the switches to the existing horn activating wire necessitates a substantial design changes in the current steering wheel.
However, electronic circuits mounted on a motor vehicle are subject to voltage supply variations and noise. Even under such unfavorable environments, the switched signal supplied through a common conductor must be sharply discriminated for reliable operation.